No abstract

Background and objectives: Endometrial polyps in asymptomatic postmenopausal women are often incidentally found, yet only 1.51% of them are malignant. Their potential for malignant transformation has not been adequately addressed. The aim of this study was to investigate the proliferation within endometrial polyps as one of the indicators of their malignization potential in asymptomatic postmenopausal women. Materials and Methods: Immunohistochemical studies of Ki-67 were performed. Cases included 52 benign postmenopausal polyps, 19 endometrioid carcinoma with coexisting benign polyps, 12 polyps with foci of carcinoma and 4 cases of polyps, which later developed carcinoma. The control group included 31 atrophic endometria and 32 benign premenopausal polyps. Ki-67 was scored in either 10 or 20 “hot spot” fields, as percentage of positively stained cells. Results: The median epithelial Ki-67 score in postmenopausal benign polyps (4.7%) was significantly higher than in atrophic endometria (2.41%, p < 0.0001) and significantly lower than in premenopausal benign polyps (11.4%, p = 0.003) and endometrial cancer (8.3%, p < 0.0001). Where endometrial polyps were found in association with endometrial carcinoma, Ki-67 was significantly higher in cancer (p < 0.0001). No significant difference was found between Ki-67 scores of cancer focus and of the polyps tissue itself, respectively 2.8% and 4.55%, p = 0.37. Ki-67 expression, where polyps were resected and women later developed cancer, was not significantly different (p = 0.199). Conclusion: Polyps from asymptomatic postmenopausal women showed significantly more proliferation in both epithelial and stromal components than inactive atrophic endometria but less than premenopausal benign polyps and/or endometrial cancer. Benign postmenopausal endometrial polyps exhibit low proliferative activity, suggesting low malignant potential and may not require resection in asymptomatic women.

Background/Aim: To investigate tumor suppression as an indicator of malignization potential within endometrial polyps in asymptomatic postmenopausal women. Materials and Methods: Immunohistochemical studies of the phosphatase and tensin homolog (PTEN) were performed. Cases included 52 benign postmenopausal polyps, 19 endometrioid carcinomas with coexisting benign polyps, and 12 polyps with foci of carcinoma. Controls included 31 atrophic endometria and 32 benign premenopausal polyps. PTEN was scored by quantitative methods according to staining intensity. Results: The mean epithelial and stromal PTEN H-score in postmenopausal benign endometrial polyps (193.8 and 123.2, respectively) was significantly higher than that in the atrophic endometrium (135.5 and 90.2, p=0.008), and premenopausal benign endometrial polyps (100.7 and 198.7, p<0.001). Significant difference between postmenopausal endometrial polyps and endometrial carcinoma was noticed in the epithelial compartment (193.8 vs. 65.7, respectively, p<0. 001). Conclusion: Asymptomatic benign postmenopausal polyps have a distinctively high tumor suppression compared with endometrial cancer, suggesting low malignization potential.Endometrial polyps (EPs) are localized projections of endometrial tissue found in approximately 30% of women in the western world and are commonly considered benign endometrial lesions (1-4).Hysteroscopic polypectomy is the gold standard to treat symptomatic endometrial polyps, to obtain specimens for histological evaluation, and to provide a relatively safe and cost-effective secondary prevention of endometrial cancer (EC) (5, 6). Widespread use of gynaecological ultrasonography has led to improved detection of asymptomatic endometrial polyps (6, 7). The management of asymptomatic postmenopausal women with incidentally identified EPs is still a matter of debate, as the association of these EPs with malignancy is low and accounts for 0.1-1.51%, compared with 4.47% in symptomatic EPs (4,6,[8][9][10][11].Phosphatase and tensin homolog (PTEN) mutations and deletions are the most frequent genetic alterations seen in endometrioid endometrial cancer with genetic inactivation found in approximately 80% of cases (12,13). Immunohistochemical (IHC) analysis is a widely used technique capable to detect specific antigens in tissue samples, predict the course of the disease, and help in treatment decisions. Therefore, among the proteins that might be used as biological markers of endometrial cancer, one responsible for tumor suppression (PTEN), is expected to give a better understanding at the molecular level.Accordingly, considering the high incidence of PTEN alterations in EC and given the lack of data on the potential for malignant transformation in asymptomatic postmenopausal polyps, the present study was conducted to investigate tumor suppression in postmenopausal endometrial polyps as one of the indicators of their malignization potential in asymptomatic women.